"""
    sphinx.builders.latex
    ~~~~~~~~~~~~~~~~~~~~~

    LaTeX builder.

    :copyright: Copyright 2007-2020 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

import os
from os import path
from typing import Any, Dict, Iterable, List, Tuple, Union

from docutils.frontend import OptionParser
from docutils.nodes import Node

import sphinx.builders.latex.nodes  # NOQA  # Workaround: import this before writer to avoid ImportError
from sphinx import package_dir, addnodes, highlighting
from sphinx.application import Sphinx
from sphinx.builders import Builder
from sphinx.builders.latex.constants import ADDITIONAL_SETTINGS, DEFAULT_SETTINGS, SHORTHANDOFF
from sphinx.builders.latex.theming import Theme, ThemeFactory
from sphinx.builders.latex.util import ExtBabel
from sphinx.config import Config, ENUM
from sphinx.environment.adapters.asset import ImageAdapter
from sphinx.errors import NoUri, SphinxError
from sphinx.locale import _, __
from sphinx.util import texescape, logging, progress_message, status_iterator
from sphinx.util.console import bold, darkgreen  # type: ignore
from sphinx.util.docutils import SphinxFileOutput, new_document
from sphinx.util.fileutil import copy_asset_file
from sphinx.util.i18n import format_date
from sphinx.util.nodes import inline_all_toctrees
from sphinx.util.osutil import SEP, make_filename_from_project
from sphinx.util.template import LaTeXRenderer
from sphinx.writers.latex import LaTeXWriter, LaTeXTranslator

# load docutils.nodes after loading sphinx.builders.latex.nodes
from docutils import nodes  # NOQA


XINDY_LANG_OPTIONS = {
    # language codes from docutils.writers.latex2e.Babel
    # ! xindy language names may differ from those in use by LaTeX/babel
    # ! xindy does not support all Latin scripts as recognized by LaTeX/babel
    # ! not all xindy-supported languages appear in Babel.language_codes
    # cd /usr/local/texlive/2018/texmf-dist/xindy/modules/lang
    # find . -name '*utf8.xdy'
    # LATIN
    'sq': '-L albanian -C utf8 ',
    'hr': '-L croatian -C utf8 ',
    'cs': '-L czech -C utf8 ',
    'da': '-L danish -C utf8 ',
    'nl': '-L dutch-ij-as-ij -C utf8 ',
    'en': '-L english -C utf8 ',
    'eo': '-L esperanto -C utf8 ',
    'et': '-L estonian -C utf8 ',
    'fi': '-L finnish -C utf8 ',
    'fr': '-L french -C utf8 ',
    'de': '-L german-din5007 -C utf8 ',
    'is': '-L icelandic -C utf8 ',
    'it': '-L italian -C utf8 ',
    'la': '-L latin -C utf8 ',
    'lv': '-L latvian -C utf8 ',
    'lt': '-L lithuanian -C utf8 ',
    'dsb': '-L lower-sorbian -C utf8 ',
    'ds': '-L lower-sorbian -C utf8 ',   # trick, no conflict
    'nb': '-L norwegian -C utf8 ',
    'no': '-L norwegian -C utf8 ',       # and what about nynorsk?
    'pl': '-L polish -C utf8 ',
    'pt': '-L portuguese -C utf8 ',
    'ro': '-L romanian -C utf8 ',
    'sk': '-L slovak-small -C utf8 ',    # there is also slovak-large
    'sl': '-L slovenian -C utf8 ',
    'es': '-L spanish-modern -C utf8 ',  # there is also spanish-traditional
    'sv': '-L swedish -C utf8 ',
    'tr': '-L turkish -C utf8 ',
    'hsb': '-L upper-sorbian -C utf8 ',
    'hs': '-L upper-sorbian -C utf8 ',   # trick, no conflict
    'vi': '-L vietnamese -C utf8 ',
    # CYRILLIC
    # for usage with pdflatex, needs also cyrLICRutf8.xdy module
    'be': '-L belarusian -C utf8 ',
    'bg': '-L bulgarian -C utf8 ',
    'mk': '-L macedonian -C utf8 ',
    'mn': '-L mongolian-cyrillic -C utf8 ',
    'ru': '-L russian -C utf8 ',
    'sr': '-L serbian -C utf8 ',
    'sh-cyrl': '-L serbian -C utf8 ',
    'sh': '-L serbian -C utf8 ',         # trick, no conflict
    'uk': '-L ukrainian -C utf8 ',
    # GREEK
    # can work only with xelatex/lualatex, not supported by texindy+pdflatex
    'el': '-L greek -C utf8 ',
    # FIXME, not compatible with [:2] slice but does Sphinx support Greek ?
    'el-polyton': '-L greek-polytonic -C utf8 ',
}

XINDY_CYRILLIC_SCRIPTS = [
    'be', 'bg', 'mk', 'mn', 'ru', 'sr', 'sh', 'uk',
]

logger = logging.getLogger(__name__)


class LaTeXBuilder(Builder):
    """
    Builds LaTeX output to create PDF.
    """
    name = 'latex'
    format = 'latex'
    epilog = __('The LaTeX files are in %(outdir)s.')
    if os.name == 'posix':
        epilog += __("\nRun 'make' in that directory to run these through "
                     "(pdf)latex\n"
                     "(use `make latexpdf' here to do that automatically).")

    supported_image_types = ['application/pdf', 'image/png', 'image/jpeg']
    supported_remote_images = False
    default_translator_class = LaTeXTranslator

    def init(self) -> None:
        self.babel = None           # type: ExtBabel
        self.context = {}           # type: Dict[str, Any]
        self.docnames = []          # type: Iterable[str]
        self.document_data = []     # type: List[Tuple[str, str, str, str, str, bool]]
        self.themes = ThemeFactory(self.app)
        self.usepackages = self.app.registry.latex_packages
        texescape.init()

        self.init_context()
        self.init_babel()
        self.init_multilingual()

    def get_outdated_docs(self) -> Union[str, List[str]]:
        return 'all documents'  # for now

    def get_target_uri(self, docname: str, typ: str = None) -> str:
        if docname not in self.docnames:
            raise NoUri(docname, typ)
        else:
            return '%' + docname

    def get_relative_uri(self, from_: str, to: str, typ: str = None) -> str:
        # ignore source path
        return self.get_target_uri(to, typ)

    def init_document_data(self) -> None:
        preliminary_document_data = [list(x) for x in self.config.latex_documents]
        if not preliminary_document_data:
            logger.warning(__('no "latex_documents" config value found; no documents '
                              'will be written'))
            return
        # assign subdirs to titles
        self.titles = []  # type: List[Tuple[str, str]]
        for entry in preliminary_document_data:
            docname = entry[0]
            if docname not in self.env.all_docs:
                logger.warning(__('"latex_documents" config value references unknown '
                                  'document %s'), docname)
                continue
            self.document_data.append(entry)  # type: ignore
            if docname.endswith(SEP + 'index'):
                docname = docname[:-5]
            self.titles.append((docname, entry[2]))

    def init_context(self) -> None:
        self.context = DEFAULT_SETTINGS.copy()

        # Add special settings for latex_engine
        self.context.update(ADDITIONAL_SETTINGS.get(self.config.latex_engine, {}))

        # Add special settings for (latex_engine, language_code)
        if self.config.language:
            key = (self.config.latex_engine, self.config.language[:2])
            self.context.update(ADDITIONAL_SETTINGS.get(key, {}))

        # Apply extension settings to context
        self.context['packages'] = self.usepackages

        # Apply user settings to context
        self.context.update(self.config.latex_elements)
        self.context['release'] = self.config.release
        self.context['use_xindy'] = self.config.latex_use_xindy

        if self.config.today:
            self.context['date'] = self.config.today
        else:
            self.context['date'] = format_date(self.config.today_fmt or _('%b %d, %Y'),
                                               language=self.config.language)

        if self.config.latex_logo:
            self.context['logofilename'] = path.basename(self.config.latex_logo)

        # for compatibilities
        self.context['indexname'] = _('Index')
        if self.config.release:
            # Show the release label only if release value exists
            self.context.setdefault('releasename', _('Release'))

    def init_babel(self) -> None:
        self.babel = ExtBabel(self.config.language, not self.context['babel'])
        if self.config.language and not self.babel.is_supported_language():
            # emit warning if specified language is invalid
            # (only emitting, nothing changed to processing)
            logger.warning(__('no Babel option known for language %r'),
                           self.config.language)

    def init_multilingual(self) -> None:
        if self.context['latex_engine'] == 'pdflatex':
            if not self.babel.uses_cyrillic():
                if 'X2' in self.context['fontenc']:
                    self.context['substitutefont'] = '\\usepackage{substitutefont}'
                    self.context['textcyrillic'] = '\\usepackage[Xtwo]{sphinxcyrillic}'
                elif 'T2A' in self.context['fontenc']:
                    self.context['substitutefont'] = '\\usepackage{substitutefont}'
                    self.context['textcyrillic'] = '\\usepackage[TtwoA]{sphinxcyrillic}'
            if 'LGR' in self.context['fontenc']:
                self.context['substitutefont'] = '\\usepackage{substitutefont}'
            else:
                self.context['textgreek'] = ''

        # 'babel' key is public and user setting must be obeyed
        if self.context['babel']:
            self.context['classoptions'] += ',' + self.babel.get_language()
            # this branch is not taken for xelatex/lualatex if default settings
            self.context['multilingual'] = self.context['babel']
            if self.config.language:
                self.context['shorthandoff'] = SHORTHANDOFF

                # Times fonts don't work with Cyrillic languages
                if self.babel.uses_cyrillic() and 'fontpkg' not in self.config.latex_elements:
                    self.context['fontpkg'] = ''
        elif self.context['polyglossia']:
            self.context['classoptions'] += ',' + self.babel.get_language()
            options = self.babel.get_mainlanguage_options()
            if options:
                language = r'\setmainlanguage[%s]{%s}' % (options, self.babel.get_language())
            else:
                language = r'\setmainlanguage{%s}' % self.babel.get_language()

            self.context['multilingual'] = '%s\n%s' % (self.context['polyglossia'], language)

    def write_stylesheet(self) -> None:
        highlighter = highlighting.PygmentsBridge('latex', self.config.pygments_style)
        stylesheet = path.join(self.outdir, 'sphinxhighlight.sty')
        with open(stylesheet, 'w') as f:
            f.write('\\NeedsTeXFormat{LaTeX2e}[1995/12/01]\n')
            f.write('\\ProvidesPackage{sphinxhighlight}'
                    '[2016/05/29 stylesheet for highlighting with pygments]\n\n')
            f.write(highlighter.get_stylesheet())

    def write(self, *ignored: Any) -> None:
        docwriter = LaTeXWriter(self)
        docsettings = OptionParser(
            defaults=self.env.settings,
            components=(docwriter,),
            read_config_files=True).get_default_values()  # type: Any

        self.init_document_data()
        self.write_stylesheet()

        for entry in self.document_data:
            docname, targetname, title, author, themename = entry[:5]
            theme = self.themes.get(themename)
            toctree_only = False
            if len(entry) > 5:
                toctree_only = entry[5]
            destination = SphinxFileOutput(destination_path=path.join(self.outdir, targetname),
                                           encoding='utf-8', overwrite_if_changed=True)
            with progress_message(__("processing %s") % targetname):
                doctree = self.env.get_doctree(docname)
                toctree = next(iter(doctree.traverse(addnodes.toctree)), None)
                if toctree and toctree.get('maxdepth') > 0:
                    tocdepth = toctree.get('maxdepth')
                else:
                    tocdepth = None

                doctree = self.assemble_doctree(
                    docname, toctree_only,
                    appendices=(self.config.latex_appendices if theme.name != 'howto' else []))
                doctree['docclass'] = theme.docclass
                doctree['contentsname'] = self.get_contentsname(docname)
                doctree['tocdepth'] = tocdepth
                self.post_process_images(doctree)
                self.update_doc_context(title, author, theme)

            with progress_message(__("writing")):
                docsettings._author = author
                docsettings._title = title
                docsettings._contentsname = doctree['contentsname']
                docsettings._docname = docname
                docsettings._docclass = theme.name

                doctree.settings = docsettings
                docwriter.theme = theme
                docwriter.write(doctree, destination)

    def get_contentsname(self, indexfile: str) -> str:
        tree = self.env.get_doctree(indexfile)
        contentsname = None
        for toctree in tree.traverse(addnodes.toctree):
            if 'caption' in toctree:
                contentsname = toctree['caption']
                break

        return contentsname

    def update_doc_context(self, title: str, author: str, theme: Theme) -> None:
        self.context['title'] = title
        self.context['author'] = author
        self.context['docclass'] = theme.docclass
        self.context['papersize'] = theme.papersize
        self.context['pointsize'] = theme.pointsize
        self.context['wrapperclass'] = theme.wrapperclass

    def assemble_doctree(self, indexfile: str, toctree_only: bool, appendices: List[str]) -> nodes.document:  # NOQA
        self.docnames = set([indexfile] + appendices)
        logger.info(darkgreen(indexfile) + " ", nonl=True)
        tree = self.env.get_doctree(indexfile)
        tree['docname'] = indexfile
        if toctree_only:
            # extract toctree nodes from the tree and put them in a
            # fresh document
            new_tree = new_document('<latex output>')
            new_sect = nodes.section()
            new_sect += nodes.title('<Set title in conf.py>',
                                    '<Set title in conf.py>')
            new_tree += new_sect
            for node in tree.traverse(addnodes.toctree):
                new_sect += node
            tree = new_tree
        largetree = inline_all_toctrees(self, self.docnames, indexfile, tree,
                                        darkgreen, [indexfile])
        largetree['docname'] = indexfile
        for docname in appendices:
            appendix = self.env.get_doctree(docname)
            appendix['docname'] = docname
            largetree.append(appendix)
        logger.info('')
        logger.info(__("resolving references..."))
        self.env.resolve_references(largetree, indexfile, self)
        # resolve :ref:s to distant tex files -- we can't add a cross-reference,
        # but append the document name
        for pendingnode in largetree.traverse(addnodes.pending_xref):
            docname = pendingnode['refdocname']
            sectname = pendingnode['refsectname']
            newnodes = [nodes.emphasis(sectname, sectname)]  # type: List[Node]
            for subdir, title in self.titles:
                if docname.startswith(subdir):
                    newnodes.append(nodes.Text(_(' (in '), _(' (in ')))
                    newnodes.append(nodes.emphasis(title, title))
                    newnodes.append(nodes.Text(')', ')'))
                    break
            else:
                pass
            pendingnode.replace_self(newnodes)
        return largetree

    def finish(self) -> None:
        self.copy_image_files()
        self.write_message_catalog()
        self.copy_support_files()

        if self.config.latex_additional_files:
            self.copy_latex_additional_files()

    @progress_message(__('copying TeX support files'))
    def copy_support_files(self) -> None:
        """copy TeX support files from texinputs."""
        # configure usage of xindy (impacts Makefile and latexmkrc)
        # FIXME: convert this rather to a confval with suitable default
        #        according to language ? but would require extra documentation
        if self.config.language:
            xindy_lang_option = \
                XINDY_LANG_OPTIONS.get(self.config.language[:2],
                                       '-L general -C utf8 ')
            xindy_cyrillic = self.config.language[:2] in XINDY_CYRILLIC_SCRIPTS
        else:
            xindy_lang_option = '-L english -C utf8 '
            xindy_cyrillic = False
        context = {
            'latex_engine':      self.config.latex_engine,
            'xindy_use':         self.config.latex_use_xindy,
            'xindy_lang_option': xindy_lang_option,
            'xindy_cyrillic':    xindy_cyrillic,
        }
        logger.info(bold(__('copying TeX support files...')))
        staticdirname = path.join(package_dir, 'texinputs')
        for filename in os.listdir(staticdirname):
            if not filename.startswith('.'):
                copy_asset_file(path.join(staticdirname, filename),
                                self.outdir, context=context)

        # use pre-1.6.x Makefile for make latexpdf on Windows
        if os.name == 'nt':
            staticdirname = path.join(package_dir, 'texinputs_win')
            copy_asset_file(path.join(staticdirname, 'Makefile_t'),
                            self.outdir, context=context)

    @progress_message(__('copying additional files'))
    def copy_latex_additional_files(self) -> None:
        for filename in self.config.latex_additional_files:
            logger.info(' ' + filename, nonl=True)
            copy_asset_file(path.join(self.confdir, filename), self.outdir)

    def copy_image_files(self) -> None:
        if self.images:
            stringify_func = ImageAdapter(self.app.env).get_original_image_uri
            for src in status_iterator(self.images, __('copying images... '), "brown",
                                       len(self.images), self.app.verbosity,
                                       stringify_func=stringify_func):
                dest = self.images[src]
                try:
                    copy_asset_file(path.join(self.srcdir, src),
                                    path.join(self.outdir, dest))
                except Exception as err:
                    logger.warning(__('cannot copy image file %r: %s'),
                                   path.join(self.srcdir, src), err)
        if self.config.latex_logo:
            if not path.isfile(path.join(self.confdir, self.config.latex_logo)):
                raise SphinxError(__('logo file %r does not exist') % self.config.latex_logo)
            else:
                copy_asset_file(path.join(self.confdir, self.config.latex_logo), self.outdir)

    def write_message_catalog(self) -> None:
        formats = self.config.numfig_format
        context = {
            'addtocaptions': r'\@iden',
            'figurename': formats.get('figure', '').split('%s', 1),
            'tablename': formats.get('table', '').split('%s', 1),
            'literalblockname': formats.get('code-block', '').split('%s', 1)
        }

        if self.context['babel'] or self.context['polyglossia']:
            context['addtocaptions'] = r'\addto\captions%s' % self.babel.get_language()

        filename = path.join(package_dir, 'templates', 'latex', 'sphinxmessages.sty_t')
        copy_asset_file(filename, self.outdir, context=context, renderer=LaTeXRenderer())


def validate_config_values(app: Sphinx, config: Config) -> None:
    for key in list(config.latex_elements):
        if key not in DEFAULT_SETTINGS:
            msg = __("Unknown configure key: latex_elements[%r], ignored.")
            logger.warning(msg % (key,))
            config.latex_elements.pop(key)


def validate_latex_theme_options(app: Sphinx, config: Config) -> None:
    for key in list(config.latex_theme_options):
        if key not in Theme.UPDATABLE_KEYS:
            msg = __("Unknown theme option: latex_theme_options[%r], ignored.")
            logger.warning(msg % (key,))
            config.latex_theme_options.pop(key)


def default_latex_engine(config: Config) -> str:
    """ Better default latex_engine settings for specific languages. """
    if config.language == 'ja':
        return 'platex'
    elif (config.language or '').startswith('zh'):
        return 'xelatex'
    elif config.language == 'el':
        return 'xelatex'
    else:
        return 'pdflatex'


def default_latex_docclass(config: Config) -> Dict[str, str]:
    """ Better default latex_docclass settings for specific languages. """
    if config.language == 'ja':
        if config.latex_engine == 'uplatex':
            return {'manual': 'ujbook',
                    'howto': 'ujreport'}
        else:
            return {'manual': 'jsbook',
                    'howto': 'jreport'}
    else:
        return {}


def default_latex_use_xindy(config: Config) -> bool:
    """ Better default latex_use_xindy settings for specific engines. """
    return config.latex_engine in {'xelatex', 'lualatex'}


def default_latex_documents(config: Config) -> List[Tuple[str, str, str, str, str]]:
    """ Better default latex_documents settings. """
    project = texescape.escape(config.project, config.latex_engine)
    author = texescape.escape(config.author, config.latex_engine)
    return [(config.master_doc,
             make_filename_from_project(config.project) + '.tex',
             texescape.escape_abbr(project),
             texescape.escape_abbr(author),
             config.latex_theme)]


def setup(app: Sphinx) -> Dict[str, Any]:
    app.setup_extension('sphinx.builders.latex.transforms')

    app.add_builder(LaTeXBuilder)
    app.connect('config-inited', validate_config_values, priority=800)
    app.connect('config-inited', validate_latex_theme_options, priority=800)

    app.add_config_value('latex_engine', default_latex_engine, None,
                         ENUM('pdflatex', 'xelatex', 'lualatex', 'platex', 'uplatex'))
    app.add_config_value('latex_documents', default_latex_documents, None)
    app.add_config_value('latex_logo', None, None, [str])
    app.add_config_value('latex_appendices', [], None)
    app.add_config_value('latex_use_latex_multicolumn', False, None)
    app.add_config_value('latex_use_xindy', default_latex_use_xindy, None, [bool])
    app.add_config_value('latex_toplevel_sectioning', None, None,
                         ENUM(None, 'part', 'chapter', 'section'))
    app.add_config_value('latex_domain_indices', True, None, [list])
    app.add_config_value('latex_show_urls', 'no', None)
    app.add_config_value('latex_show_pagerefs', False, None)
    app.add_config_value('latex_elements', {}, None)
    app.add_config_value('latex_additional_files', [], None)
    app.add_config_value('latex_theme', 'manual', None, [str])
    app.add_config_value('latex_theme_options', {}, None)
    app.add_config_value('latex_theme_path', [], None, [list])

    app.add_config_value('latex_docclass', default_latex_docclass, None)

    return {
        'version': 'builtin',
        'parallel_read_safe': True,
        'parallel_write_safe': True,
    }
